1. Field of the Invention
This invention relates generally to hand tools and more specifically to a small hand tool that is particularly adapted to removing air filters from the plenum of large air management systems.
2. Description of the Prior Art
In large applications, air conditioning systems are classified as air management systems. This is the result of the many functions they perform. A typical large system will not only heat and cool the air but it will humidify, in the winter, dehumidify in the summer and electrostatically falter the air year round. Systems of this magnitude utilize large blowers to move massive amounts of air through hundreds of feet of duct work. Engineers, designing such systems, work provide maximum efficiency in order to reduce operating costs. Placement of the equipment for ease of maintenance is a secondary consideration. As a result, frequently maintained items such as air filters are located in places fairly far removed from service openings. In these situations filters are equipped with some type of retrieval means. Since the retrieval means is only meant to be used once and then discarded, they tend to be very light duty and break on a regular basis. The enterprising technician will then use his tape measure, catching the hook at the end to snag the edge of the filter and dislodge it for removal.
Similarly, it is not uncommon for objects to enter the system and become blocked by the filter. Some of this blockage may be removed by use of an industrial vacuum cleaner. Other items, particularly metal items, may be too heavy to vacuum and may only conveniently be removed by means of a magnet.
The need then, is for a small, light weight, extendable hand tool adapted to receive the appropriate accessories to retrieve air filters of the type described in an efficient manner without destroying the dirty filter and redistributing the collected dirt within duct, and accessories to retrieve metal debris not collectible by conventional means.
The following U.S. Patents show telescoping tubes with locking arrangements to allow the sliding sections to be secured one to another: U.S. Pat No. 4,329,076 issued May 11, 1982 to Coreth, U.S. Pat. No. 4,793,646 issued Dec. 27, 1988 to Michaud, Jr. and U.S. Pat. No. 5,220,707 issued Jun. 22, 1993 to Newman, Sr. et al. The U.S. Pat. No. 4,881,338 issued Nov. 21, 1989 to Lung shows a permanently attached gaff hook having a tubular body and a plurality of telescoping sections. U.S. Pat. No. 5,099,539 issued Mar. 31, 1992 to Forester discloses a telescoping extension rod having an adjustable tool head.
The prior cited does not show a tool that could be carried on a technician's tool belt and still be able to reach into the duct work and extract the filters or debris as suggested in this invention.